1. Field of the Invention
The present invention relates to a lighting unit, and in particular relates to a lighting unit which can prevent yellow halos.
2. Description of the Related Art
White light emitting diodes generally have yellow halo problem caused by non-uniformed phosphor powder spread. The yellow halo problem is enhanced when the white emitting diodes are applied with spotlight optical elements. Conventionally, to prevent yellow halo, a nebulized area is formed on a light emitting surface of the spotlight optical element. However, the nebulized area increases light emitting angle (at least 5°), which hinders small light emitting angle requirements. Also, light maxing effect of the nebulized area is insufficient, which decreases reduction of the yellow halo.